The rate at which data are transmitted through communication networks has dramatically increased in recent years, fueled by progresses achieved in fiber and optoelectronic devices and techniques, such as DWDM (Dense Wavelength Division Multiplexing), which allows multiplication of the bandwidth of a single fiber by merging many wavelengths on it. As a result, telecommunications and networking industry had to develop devices capable of routing and switching the resulting huge amount of data that converge and must be dispatched at each network node. Typically, routers and switches situated at those network nodes have now to cope with the requirement of having to move data at aggregate rates that must be expressed in hundredths of giga (109) bits per second while multi tera (1012) bits per second rates must be considered for the new devices under development.
Even though considerable progress has been made in optoelectronics, allowing high levels of performance in the transport of data from node to node, it remains that switching and routing of the data is still done in the electrical domain at each network node. Working in electrical domain occurs because there is no optical memory available yet that would permit storing temporarily the frames of transmitted data while they are examined to determine their final destination. This must still be done in the electrical domain using the traditional semiconductor technologies and memories.
Improvements in semiconductor processes are making it possible to develop integrated circuits of increasing size and complexity. As a consequence, since the clock rates reach very high frequency, signals carrying data must be of high quality to detect logic levels. However, signals carrying data are subject to attenuation and distortion resulting from transmission media properties. To reduce the number of transmission errors, a correction mechanism, e.g. an equalizer, or a distortion compensation, e.g., a Finite Impulse Response (FIR) filter, is generally implemented in the transmission system. Correction mechanism is implemented in the receiver side while distortion compensation mechanism is implemented in the emitter side. It is generally advantageous to compensate distortion prior to transmission. Distortion compensation mechanisms could be, i.e., parameters are automatically evaluated, or determined by simulating the behavior of the transmission media.
Even though automatic mechanisms present the advantage of providing adapted parameter values, they are surface and power consuming. For this reason, integrated communication systems, such as switches or routers, are generally using distortion compensation mechanisms where parameters are determined by simulation and could be ‘manually’ adjusted.
Therefore, there is a need for a method and systems for automatically determining the parameter values of signal emitting means, without increasing their complexity nor their power consumption.